Photovoltaic solar electric systems, the most environmentally friendly way of generating electricity, are typically comprised of a plurality of solar modules, which are coupled together and then mounted on a roof of a building or a dedicated ground or pole mounted frame. FIG. 1 illustrates a conventional solar panel assembly 10 with underlying rails for attachment. The solar panel in this embodiment comprises three solar modules, 12A-12C. One of ordinary skill in the art recognizes there could be any number of modules and they could be in various configurations to form a solar panel that when turned over attaches directly to a roof or a mounting system through multiple penetrations via the rails 24.
Each of the solar panel modules 12A-12C includes a junction box 14A-14C which receives cables 16, which are applied in serial fashion from one module to the next. Also included within each of these modules 12A-12C is an electrical ground wire assembly 18, which is used to ground the modules and the underlying frame at the appropriate points. In addition, each of the modules includes extra wiring from nearby modules that must be wrapped and tied down in between, as shown at 20A and 20B to ensure that the wires do not get damaged. FIG. 1A is a view of the grounding screw for the solar panel. The screw or bolt assembly 22, which must be provided in several places, attaches the ground wire assembly 18 to each piece of equipment in the assembly at least once, in this case five (5) places, on each of the solar modules 12A-12C and underlying frame, thereby creating a grounded assembly.
Referring back in FIG. 1, the two metal rails 24 that extend in parallel with and along the length of the solar modules 12A-12C form the underlying support structure for the solar modules. The rails are attached to the roof so that the entire solar panel can be mounted in a single rigid geometric plane on the roof, thereby improving the durability and aesthetics of the installation. In some cases the rails are mounted to the roof first (attached to the roof with L shaped brackets and lag bolts to the underlying rafters), and then the modules are attached to the rails with bolt-fastened clips, In other cases, as shown in FIG. 1B, the rails are attached to the modules first (in this case with hex nuts and bolts or in other cases clips), and then the entire module-rail assembly (or panel) is attached to the roof with L shaped brackets 26 (FIG. 1) and lag bolts to the underlying rafters. These rails 24 are also electrically grounded as indicated above.
For ventilation and drainage purposes it is beneficial to mount the panel above the roof with a small air gap between the roof surface and underside of the modules and rails. For wiring and grounding purposes for roof assembled panels it is beneficial to have access below the modules so that wires can be connected and tied. For single geometric plan purposes it is beneficial to provide some vertical adjustability of the mounting point to account for variability (waviness) in roof surfaces. For these reasons the roof mounting bracket (whether it is an L shaped bracket or different design) generally provides some vertical adjustability (typically 1-3 inches). Moreover, roof attachments must be made to a secure underlying surface, generally a rafter. These rafters may not be consistently spaced. Therefore, the mounting rails typically include some kind of adjustable groove so that the mounting point from the rail to the roof attachment (L bracket) can be directly over a secure mounting point—wherever this point may be.
The conventional solar panel 10 requires many individual operations to construct and mount in order to provide a reliable and high performance photovoltaic solar electric systems. Mounting on uneven roof surfaces requires many small parts and adjustments.
Making sure there is airflow and drainage requires the panel to be raised off the roof slightly, but aesthetic considerations require the panel to be close to the roof. Each module in the panel must be wired together, extra wiring must be tucked away securely, and every conductive component must be electrically grounded. All the required parts and steps increase the cost of the system, which ultimately negatively affects the payback of the system. In addition, conventional solar modules are shipped in cardboard boxes on palettes, requiring additional shipping costs and substantial unpacking and cardboard disposal costs.
There are two primary types of conventional flat roof mounting systems. One conventional type is a rail type system. Some rail systems have good mechanical strength with a plurality of rails that are bolted into a roof membrane. However, the rails add weight to the roof and require using a multitude of associated mounting parts that add to the complexity of the planning, logistics, and installation process. In addition, the plurality of rails mean many roof penetrations, each penetration is a potential source of roof leaks and the securing the rails to the roof requires additional materials and labor. The rail systems are often custom built during the installation, utilizing even more labor and time. In addition, the grounding and electrical wiring required by the rail system is complex and labor intensive.
The other conventional type is a flat roof mounting system which creates a modular system via pods of panels that either attach or sit on the roof membrane or mounting system and depend on geometric design or penetrations to resist wind uplift. This type of mounting system, like the conventional rail system mount, utilizes many different parts which create planning, logistic and labor challenges. Further, as with the rail systems, the grounding and electrical wiring required by the conventional roof mounting system is complex and labor intensive. Additionally, the conventional roof mounting system is scalable, but looses structural strength as it grows in size and does not provide for versatility in configuration.
Thus, it is desirable to provide a minimal ballasted surface mounting system and method that overcomes these limitations of conventional mounting systems.